Thermal Effects and Small Signal Modulation of 1.3-μm InAs/GaAs Self-Assembled Quantum-Dot Lasers

Abstract

We investigate the influence of thermal effects on the high-speed performance of 1.3-μm InAs/GaAs quantum-dot lasers in a wide temperature range (5–50°C). Ridge waveguide devices with 1.1 mm cavity length exhibit small signal modulation bandwidths of 7.51 GHz at 5°C and 3.98 GHz at 50°C. Temperature-dependent K-factor, differential gain, and gain compression factor are studied. While the intrinsic damping-limited modulation bandwidth is as high as 23 GHz, the actual modulation bandwidth is limited by carrier thermalization under continuous wave operation. Saturation of the resonance frequency was found to be the result of thermal reduction in the differential gain, which may originate from carrier thermalization.

Improved ground-state modulation characteristics in 1.3 μm InAs/GaAs quantum dot lasers by rapid thermal annealing

“…The choice of annealing conditions was determined from our recently reported results [ 9 ]. Subsequently, the as-grown and annealed samples were processed into 4-μm-wide narrow ridge waveguide lasers [ 12 ]. The high-speed modulation of the as-cleaved QD lasers was performed under continuous-wave (CW) biasing condition using a vector network analyzer (VNA) and a high-speed photoreceiver [ 13 ].…”

The effects of thermal annealing on the photoluminescence and DC characteristics of 1.3 µm p‐doped InAs/InGaAs/GaAs quantum dot lasers

“…In this work we report on the DC characteristics of 1.3 μm doped GaAs-based InAs/InGaAs/GaAs 10-layer QD lasers that consist of either as-grown or annealed QDs [7]. To understand the physics of the QD lasers, a room temperature photoluminescence (RT-PL) study was performed for the as-grown and annealed QDs.…”

Study of modulation doping and ridge height effects in InAs/GaAs quantum dot lasers

“…In our study, we clearly demonstrated the improvement in modal gain and differential gain in p-doped QD lasers. However, the direct modulation frequency of our devices is about 7GHz [100], which is not high enough to fulfil the requirements of fibre-optic communication applications. Therefore, future studies should focus on improving high speed performance in QD lasers.…”